Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
sedimentary
Category
Organic (Often Found By Beachcombers)
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Septarian Nodule (Dragon Stone)
Septarian (composed of Calcite CaCO3, Aragonite CaCO3, and Limestone/Clay)
sedimentary
Assorted Decorative Tumbled Stones (Quartz, Sodalite, Aventurine, Calcite)
Mixed Silicates and Carbonates (SiO2, Na8(Al6Si6O24)Cl2, CaCO3)
mineral
Chert (and Flint)
Silicon Dioxide (SiO2)
sedimentary
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Magnetite
Magnetite (Fe3O4)
mineral
Rhodonite
Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3
mineral
Unakite
Epidotized Granite
metamorphic
Red Jasper (Quartz)
Silicon Dioxide (SiO2) with Iron impurities
sedimentary
Rhodonite
Rhodonite (Mn, Fe, Mg, Ca)SiO3
mineral
Jasper (likely Kambaba or Crocodile Jasper variety)
Silicon Dioxide (SiO2) with inclusions
sedimentary
Unakite
Epidotized Granite
metamorphic
Granite
Phaneritic Acidic Igneous Rock (Granite Group)
igneous
Ironstone (with possible Hematite/Limonite coating)
Ironstone (Fe-rich sedimentary rock)
sedimentary
Granite
Granite (Phaneritic Quartz-Feldspar Rock)
igneous
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
mineral
Unakite
Unakite epidotized granite
metamorphic
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2 (Calcium magnesium iron silicate hydroxide)
metamorphic
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
mineral
Chert (with Quartz/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Opal
Hydrated silica (SiO2·nH2O)
mineraloid
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
mineral
Granite
Granite (Phaneritic intrusive igneous rock) - Composition: SiO2, Al2O3, K2O, Na2O
igneous
Quartz Pebble (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
mineral
White Topaz
Topaz - Al2SiO4(F,OH)2
mineral
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
igneous
Tiger's Eye
SiO2 (Pseudomorph of Quartz after Crocidolite)
metamorphic
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Granite
Granite (Felsic Plutonic Rock)
igneous
Hematite / Goethite (Iron Ore)
Iron Oxide (Fe2O3 / FeO(OH))
mineral
Fluorite (Green Fluorite)
Calcium Fluoride (CaF2)
mineral
Pink Granite
Phaneritic Acidic Plutonic Rock (primarily K-feldspar, quartz, and plagioclase)
Igneous
Peacock Ore (Chalcopyrite)
Chalcopyrite (CuFeS2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
mineral
Chrysoberyl (Cyclic Twin)
Beryllium Aluminum Oxide (BeAl2O4)
mineral
Sandstone
Arenite
sedimentary
Limonite stained Sandstone
Sedimentary rock with Goethite/Limonite (FeO(OH)·nH2O)
sedimentary
Calcite Geode
Calcium Carbonate (CaCO3)
mineral
Basalt
Mafic Igneous Rock
igneous
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
igneous
Sapphire
Corundum (Al2O3)
mineral